As big as 6-foot-6-inch, 265-pound Rob Gronkowski is physically, now that he seems to be back to his normal self on the football field, his impact on the Patriots’ offense has been just as large.

Since the fourth-year tight end made his return against the Jets in Week 7 after sitting out the first six games of the season as he recovered from multiple arm surgeries as well as a back procedure, New England has looked a lot more like the offense that put up impressive numbers week after week in recent years, not the sputtering unit it was without him.

It might not all be the return of Gronkowski, of course. Over the first six games of the season, Tom Brady was also dealing with injuries to Danny Amendola and Shane Vereen, and for stretches was left with only Julian Edelman as a familiar target as he also tried to work rookies Aaron Dobson, Kenbrell Thompkins, and Josh Boyce into the fold.

But Gronkowski has been back for six games, and some of the numbers for the Patriots’ offense with and without him are stark:

■ Over the first six games of the season, Brady was 136 of 239, a completion percentage of just 56.9. Since then, he’s 150 for 232, or 64.7 percent.

■ Without Gronkowski available, and with Michael Hoomanawanui and Matthew Mulligan as the only tight ends, just 6.7 percent of Brady’s attempts went to players at the position. Since then, it’s 26.3 percent of his attempts, almost exclusively going to Gronkowski.

■ In the first six games of the season, Brady was averaging 6.2 yards per passing attempt, which would have been the lowest of his career, and over the last six that number has spiked to 7.7 YPA, much closer to where he’s been since 2007.

■ As a team, New England has seen a big improvement in red-zone efficiency, with just nine touchdowns in 22 opportunities (40.9 percent) pre-Gronkowski, and 19 touchdowns in 28 opportunities (67.9 percent) post, and also in points per game — 20.8 without the All-Pro in the lineup, 32.8 PPG with him.

It isn’t hard for Browns coach Rob Chudzinski, whose teams visits Gillette Stadium on Sunday, to see how Gronkowski’s presence has helped the Patriots’ offense.

“He’s that type of player. He’s a dynamic guy who is an impact player and you have to know where he is,” Chudzinski said. “You have to pay attention to him, and that obviously gives opportunities to other guys.

“There certainly is enough in the Patriot offense, enough guys, that they can hurt you in a lot of different ways, so it makes it very difficult when you have one of the best quarterbacks of all time getting the ball and spreading the ball around. It’s quite a challenge.”

This past week, Bill Belichick quickly said he’d offer no argument when a reporter began a question on Gronkowski by calling him one of the best in the NFL at his position.

At his best, however, it’s hard to say a current tight end is better, if we’re sticking with the traditional definition of a player at that position. New Orleans’s Jimmy Graham puts up the numbers that Gronkowski does in terms of catches and yards, but Graham isn’t at all the run blocker Gronkowski is, and earlier this season, the Patriots put cornerback Aqib Talib on Graham and Talib shut down the taller player.

Gronkowski can line up anywhere on the field, he can run all of the routes in the New England playbook, you can have him on the field regardless of the formation you want to use.

Linebackers can’t run with him, and defensive backs generally aren’t strong enough to bring him down. No matter where he goes on the field, he draws attention from at least two players, meaning one of his teammates is probably left open elsewhere.

When it comes to being a matchup difficulty, Gronkowski is in a class of his own.

“You look at tight ends across the league and what he’s able to do, a lot of times you’ll see guys who are great receivers but not necessarily good blockers, or great blockers and not necessarily the receivers, and he does them both,” Chudzinski said. “He’s outstanding at them both, and there’s not many guys around that can do that. He’s such a weapon and he’s a clutch player, and certainly Brady looks to him in those times. He’s so big, can run so well, so athletic . . .

“Who do you put on him to cover him?”

Brady certainly knows how Gronkowski has been a boon to the fortunes of the offense.

“He’s such a physical presence on the field,” Brady said. “His size, his length, and his speed, his quickness — he’s a tough matchup. Gronk always seems to have the physical advantage, it’s just a matter of if the scheme can help find a way to get him open.

“But other teams are pretty conscious of what he’s doing there. They don’t often just let him run free in the secondary or get down the field, so we’ve got to find different ways to get him the ball. If they do that, then you’ve got to throw it to the other guys. You’ve got to throw it to the other tight end, you’ve got to throw it to the receivers, the backs. That’s what really complements an offense, when you can have different things to go to when they’re taking away something that you want to go to.”

A month ago, the Steelers had such trouble accounting for everyone that not only did Gronkowski have 143 yards on nine catches, Dobson had 130 yards on five catches, and Amendola was left so open that he totaled 122 yards on just four receptions.

In recent games, still another wrinkle has been added with the return of Vereen, who can line up in the backfield, in the slot, or out wide.

Gronkowski does the majority of his work in the middle of the field, which has meant more opportunity for players on the perimeter. According to ProFootballFocus.com, Gronkowski has been targeted 59 times, 35 of those when he was in the middle-third of the field. He has 21 receptions for 352 yards and three of his four touchdowns over the middle.

“Any time you have a player that the defense tries to pay more attention to at times, it certainly helps provide the other players with more one-on-one opportunities,” said Patriots offensive coordinator Josh McDaniels. “It certainly doesn’t get them open. They have to do that on their own.”

McDaniels did note that for Edelman, Amendola, Thompkins, Vereen, and Dobson, the outside lanes have been more open.

“I think that the one thing that showed up the other day [against Houston], and it is the same thing that has shown up the past couple weeks here, is those guys have also played in just our two-receiver alignments where they are both on the perimeter — they’ve been productive there as well,” McDaniels said. “I think we’re trying to get everybody involved. We know we’ve got a lot of players that can help us out offensively and help us move the ball and score points and we’re trying to utilize them the best that we can.”